It's hard to just pick three books that every school library should have, so I'll just pick three of my favourites and share why they were important to me and my three boys.
1) Mabel Murple by Sheree Fitch - This picture book is a celebration of words with delightful illustrations. I read it to my three children countless times, and I loved it as much (if not more) than they did. The flow of this book makes it feel like a song... and what better way to engage a child and encourage a lifelong love of reading.
2) Diary of a Wimpy Kid by Jeff Kinney - This is a wonderful book for a child transitioning from picture books to chapter books. It's a funny book that is easy for kids to read... and it provides children with the opportunity to enjoy a story while gaining confidence in their ability to read "big books" on their own.
3) Harry Potter by JK Rowling - This book is perfect for older children to read alone or read aloud with their parents. It's full of magic and adventure... the perfect book to transport young readers to another world.